*3.4. Temperature Fields of the Cutting Wedge and Tribological Tests*

Figure 9 shows a graphical visualization of temperature fields in the cutting zone at the tool–chip interface section of the cutting wedge of the tool during interrupted machining 41CrS4 steel. It can be seen that the maximum temperatures develop at the tip of the cutting wedge for a tool made of HS6-5-2C material at the beginning of the working stroke (Figure 9a), but over time the region of maximum temperatures moves from the tip along the flank face. It was revealed that the presence of refractory compounds of the TiCN type (Figure 9b) in the composition of the experimental CPHSS material has a significant effect on the development of temperature fields during the working stroke of the tool. Unlike tools made of standard material, the zone of maximum temperatures remains at the top of the cutting wedge for CPHSS, the temperature rise at the very beginning of the working stroke is less intense, and their level is reduced by 20%–25%. This pattern remains for different periods of the tool's working stroke due to a significant reduction in the contact area of the material to be machined and the flank face, which has a higher hardness and a lower friction coefficient in CPHSS specimens. As can be seen from the data presented, the temperature field in the contact zone of the cutting wedge stabilizes by the end of the working stroke (at *T* = 0.1 s), and the temperature values for the two types of tool material become close. However, with a decrease in the working stroke, as shown in Figure 9, the use of CPHSS material dramatically affects the contact processes on the flank face and significantly reduces the temperature at the tip of the cutting wedge. The influence of the presence of refractory joints in the material structure on the temperature level on the main flank face is less significant and not as noticeable. However, their total effect on the development of temperature fields and the temperature level in the cutting wedge during the working stroke significantly contribute to the tool's performance, increasing its durability, as shown by performance tests under laboratory conditions (Figure 8).

**Figure 9.** Temperature fields in the cutting zone at the tool–chip interface section of the cutting wedge of a tool made of HS6-5-2C steel (**a**) and experimental CPHSS (80% HSS, 20% TiCN) (**b**), obtained at different periods *T* of the working stroke during interrupted cutting at *V* = 68 m/min, *f* = 0.15 mm/rev, *t* = 2 mm.
